Base stations and resource allocation methods thereof

A base station comprising:

• a transceiver communicating with a terminal;
• a frequency allocation unit allocating a frequency resource to the terminal through the transceiver;
• and
• an orthogonal code allocation unit generating an orthogonal code index table having multiple columns comprising a plurality of orthogonal code index combinations, each of the orthogonal code index combinations being a combination of a plurality of orthogonal codes, and allocating one of the orthogonal code combinations comprised in the orthogonal code index table to each terminal, to which the frequency resource has been allocated for a service request of the terminal, through the transceiver, such that the terminal does not have the same orthogonal code combination as other terminals, wherein at least one of a plurality of orthogonal codes comprised in the orthogonal code combination is orthogonal to at least one of a plurality of orthogonal codes comprised in an orthogonal code combination allocated to another terminal.